1. Field of the Invention
The present invention relates to an ultrasound endoscope with a transducer unit housed in a housing provided in a distal end portion of an insertion portion.
2. Description of the Related Art
Conventionally, in, e.g., medical fields, ultrasound endoscopes including an ultrasound probe at a distal end of an elongated insertion portion of an endoscope have widely been used. Each such ultrasound endoscope forms an ultrasound endoscope system jointly with, for example, an ultrasound observation apparatus and a monitor. The ultrasound endoscope system, for example, transmits ultrasound from an ultrasound probe to a subject and processes a received ultrasound echo signal in the ultrasound observation apparatus, enabling provision of an ultrasound tomographic image of an inside of the subject.
The ultrasound probe used in each such ultrasound endoscope includes, for example, a transducer unit resulting from unitization of a plurality of ultrasound transducers together with an acoustic matching layer and a back-side damping layer, and the transducer unit is housed in a housing portion formed in a housing, whereby a main part of the ultrasound probe is formed. Here, in the transducer unit, a wiring board electrically connected to the respective ultrasound transducers is provided, and a plurality of drive wirings separately extending from the cable unit so as to correspond to the respective ultrasound transducers are electrically connected to respective terminals on the wiring board, respectively. Also, in order to route the cable unit inside the insertion portion of the endoscope, a tubular wiring insertion portion (pipe portion) is provided so as to connect to the housing portion of the transducer unit formed in the housing (see, for example, Japanese Patent Application Laid-Open Publication No. 2004-209044). When such ultrasound probe is assembled, first, the work of inserting the proximal end side of the cable unit into the wiring insertion portion from the housing portion side and then pushing the group of drive wirings forking from a distal end portion of the cable unit into the wiring insertion portion and the work of housing the transducer unit in the housing portion of the housing are performed.
In such type of ultrasound endoscopes, there is a strong demand for downsizing of ultrasound probes, and examples of measures to respond to such demands may include reduction in distance from the transducer unit to a mouth of the wiring insertion portion and reduction in diameter of the wiring insertion portion.